1. Field of the Invention
The present invention relates generally to fasteners and, more specifically, to a fastener for a transport container.
2. Description of the Related Art
Fasteners that are referred to as butterfly fasteners have been known for a while, e.g. by U.S. Pat. No. 3,516,125. Such kinds of fasteners are often used in transport containers for instruments and equipment, which can be stacked in transportation mechanisms, such as airplanes and trucks. For protecting the fasteners, the fasteners are designed such that a locking mechanism does not protrude beyond the surface of the transport container by using cups, at least in the locked state.
However, it has turned out that a protrusion of the locking mechanism beyond the surface is also disadvantageous in the unlocked state, e.g. implies a danger of accident. In order to eliminate the disadvantage, a fastener known from U.S. Pat. No. 5,511,834 limits the outward motion of a fastener hook, which is effected by a spring, by means of appropriate constructive measures. Therewith, these disadvantages of the butterfly fasteners known up to then could be avoided only insufficiently.